N.H. Rev. Stat. § 4:29

The governor, with the advice and consent of the council, may acquire on behalf of the state, either by purchase or otherwise, as hereinafter provided, any real estate within the state which he may deem necessary for any military purpose, for public parks, public buildings, or for any other public improvement purposes and to accept deeds thereof in the name of the state; provided, however, that 60 days before a purchase of any real estate within the city of Concord or the Concord region, the governor shall provide written notice of such proposed purchase to the state-capitol-region planning commission. No dam or any real property appurtenant thereto or any rights and easements in either may be acquired pursuant to the authority of this section or any other provision of law except an act of the legislature which authorizes the acquisition of a particular dam, real property, or right or easement.